1. Field of the Invention
The present invention relates to a ring compression device and a ring compression method that applies force on the periphery of a ring to compress the ring and mount the ring on a mounting body located inside a bore of the ring.
2. Description of the Related Art
A ring compression device has been known in the art that is used to mount a ring onto a mounting body. The ring compression device applies force on the periphery of the ring to compress the ring and mount it onto the mounting body that is inserted inside the ring. In one conventional ring compression device, two slide members that are arranged symmetrical to each other are allowed to perform only circular movements inside an housing. Four segments that are symmetrical to each other are connected to non-concentric inner surfaces of each of the slide members. Each segment has a clamping surface that is equidistant from a center, and can move toward or away from center in the radial direction. When compressing a ring, a ring is placed inside the segments and the slide members are caused to mutually approach each other. As a result, the segments move toward the center and the radius of a circle formed by the clamping surface of each segment becomes smaller, so that force is applied on the periphery of the ring and the ring is compressed (Refer to, for instance, Japanese Patent Laid-Open Publication No. H10-575).
In another ring compression conventional device, two cams can be moved within corresponding slits by operating corresponding guide block. With movements of the two cams, two semicircular sections of a pressing machine separated from each other move in the circumferential direction, which moves the cams inside the slits. Moreover, with the movements of the cams, a press jaw is driven inward in the radial direction. A ring is placed inside the press jaw. The ring is uniformly pressed by, for example, a rubber bellow, and the bellow is fixed and jointed, for instance, to a drive shaft (Refer to, for instance, Japanese Patent Publication No. 2002-504436).
In the one conventional ring compression device, due to movement of two slide members toward each other, the segments move inward in the radial direction, and a ring placed in an inner side from the segments is compressed with a force. However, there can be an assembly error between the two slide members. When there is an assembly error, the segments do not move uniformly, and it can be difficult to apply a uniform force onto the ring.
In the another conventional ring compression device, there can be dimensional error or assembly error in any of the two semicircular sections. When there is dimensional error or assembly error, the press jaws do not move uniformly, and it can be difficult to apply uniform force to the compression ring.
Furthermore, before a ring is compressed, there are clearances between the segments or the press jaws and the ring, and between the ring and the mounting body. The clearance is required to insert the ring inside the segments or the press jaws and insert the mounting body in the ring. In each of the conventional devices, however, there is no mechanism that can hold and position the ring inside the segments or the press jaws so that the ring does not touch the segments or the press jaws, or hold and position the mounting body in the ring so that the mounting body does not touch the ring. As a result, a non-uniform force is applied to the ring, which may compress the ring in a manner that is not intended. Furthermore, a non-uniform force is applied at the center of the mounting body, which may causes the ring to fix in a manner that is not intended.
In the light of the above circumstances, an object of the present invention is to provide a ring compression device and a ring compression method that can apply a uniform force onto the ring and also facilitate positioning of the ring and the mounting body.